Since 1870-1, when J. E. Austen Leigh published his Memoir of Jane Austen, considerable additions have been made to the stock of information available for her biographers. Of these fresh sources of knowledge the set of letters from Jane to Cassandra, edited by Lord Brabourne, has been by far the most important. These letters are invaluable as memoires pour servir; although they cover only the comparatively rare periods when the two sisters were separated, and although Cassandra purposely destroyed many of the letters likely to prove the most interesting, from a distaste for publicity."